title: Is the BTS/SIGN guideline confusing? A retrospective database analysis of asthma therapy.
abstract: BACKGROUND
  The British guideline on the management of asthma produced by the British Thoracic Society (BTS) and the Scottish Intercollegiate Guidelines Network (SIGN) describes five steps for the management of chronic asthma. Combination therapy of a long acting β2-agonist (LABA) and an inhaled corticosteroid (ICS) is recommended as first-line therapy at step 3, although the dose of ICS at which to add a LABA is subject to debate.
  
  
  OBJECTIVE
  To classify the inhaled therapy prescribed to patients with asthma in NHS Forth Valley according to two interpretations of the BTS/SIGN guideline and to evaluate the use of combination therapy in this population.
  
  
  METHODS
  A retrospective analysis including patients from 46 general practitioner surgeries was conducted. Patients with physician diagnosed asthma were classified according to the BTS/SIGN guideline based on treatment prescribed during 2008. Patient characteristics were evaluated for the overall step classification, and specifically for therapy in step 3.
  
  
  RESULTS
  12,319 patients were included. Guideline interpretation resulted in a shift of 9.2% of patients (receiving medium-dose ICS alone) between steps 2 and 3. The largest proportion of patients (32.3%) was classified at step 4. Age, sex, smoking status, chronic obstructive pulmonary disease co-morbidity, and utilisation of short-acting β2-agonists and oral corticosteroids all correlated with step; however, no differences in these characteristics were evident between low-dose combination therapy and medium-dose ICS alone at step 3.
  
  
  CONCLUSIONS
  Further studies are needed to evaluate prescribing decisions in asthma. Guideline recommendations regarding the use of ICS dose escalation versus combination therapy need to be clarified relative to the published evidence.
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Covvey
authors.forename: Blair F
authors.initials: BF
authors.lastname: Johnston
authors.forename: Fraser
authors.initials: F
authors.lastname: Wood
authors.forename: Anne C
authors.initials: AC
authors.lastname: Boyter
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D058666:Adrenergic beta-2 Receptor Agonists / Q000627:therapeutic use*; D000328:Adult; D000367:Age Factors; D000368:Aged; D001249:Asthma / Q000150:complications / Q000188:drug therapy*; D015331:Cohort Studies; D016208:Databases, Factual; D004359:Drug Therapy, Combination; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000188:drug therapy; D012189:Retrospective Studies; D012737:Sex Factors; D012907:Smoking; D006113:United Kingdom
chemical_list: D000305:Adrenal Cortex Hormones; D058666:Adrenergic beta-2 Receptor Agonists